Byproducts can work in dairy rations: Make better use of byproduct feeds
Strategically, one should benefit from maximizing the use of feeds deemed bargains. As an example of how this can be accomplished, the authors balanced a ration for a 1,400-pound Holstein cow producing 80 pounds of milk per day with 3.7 percent milk fat and 3 percent milk protein using prevailing prices during the summer of 2004.
In doing so, they did not use a least-cost programming algorithm, but used ingredients that traditionally have formed the basis of a traditional Midwestern dairy cattle diet. They then modified the selection of ingredients to reflect the market conditions in January 2008.
In doing so, they reduced the amount of corn fed by 25 percent and whole cottonseed by 50 percent; eliminated wet brewers grains, 44 percent solvent-extracted soybean meal and tallow; and incorporated some dried distillers grains with solubles, corn hominy, corn gluten feed and wheat middlings.
The resulting diet is nutritionally nearly identical to the traditional Midwest dairy diet. Its cost, however, is 0.25 percent per cow per day less, resulting in an estimated savings in feed costs of more than $80 per lactation.
Although byproducts are nutritionally much more variable than grains and oilseed meals (Dairy National Research Council, 2001), their contribution to the nutritional variance of the whole diet is approximately proportional to the square of their inclusion rates, according to St-Pierre.
This doesn’t account for handling costs associated with byproducts, but inherent feed variability may not be as much of a factor as you would think. Because the 2008 diet used relatively small amounts of each of the byproducts, the resulting diet in fact has a lower expected nutritional variance for all major nutrients than when compared with the traditional diet.
Comparison of a Dairy Diet Optimized for Prevailing Feed Prices
|
Ingredients |
2004 |
2008 |
|
Lb as fed/day | ||
|
Legume hay |
4.2 |
4.2 |
|
Legume silage |
19.5 |
19.5 |
|
Corn silage |
37.0 |
37.0 |
|
Wet brewers grains |
13.8 |
0.0 |
|
Cottonseed, whole |
5.0 |
2.75 |
|
Corn grain |
15.0 |
11.25 |
|
Soybean meal, solvent, 44% |
2.25 |
0.0 |
|
Soybean meal, expeller |
2.25 |
2.75 |
|
Dried distillers grains with solubles |
0.0 |
3.33 |
|
Hominy |
0.0 |
2.25 |
|
Corn gluten feed |
0.0 |
2.75 |
|
Wheat middlings |
0.0 |
2.75 |
|
Tallow |
0.5 |
0.0 |
|
Minerals and vitamins |
1.5 |
1.5 |
|
Composition | ||
|
Dry matter (lb) |
51.3 |
51.3 |
|
Net energy for lactation (Mcal/lb) |
0.74 |
0.73 |
|
% of DM | ||
|
CP |
17.0 |
16.7 |
|
RDP |
11.3 |
10.8 |
|
RUP |
5.6 |
5.8 |
|
MP |
10.6 |
10.6 |
|
NDF |
32.2 |
33.3 |
|
NFC |
42.5 |
42.8 |
|
Ether extracts |
5.7 |
4.6 |
|
Cost in January 2008 ($/cow/day) |
4.75 |
4.50 |
Rations balanced for a 1,400-pound cow producing 80 pounds of milk/day at 3.7% fat and 3.0% true protein
By J.W. Schroeder, Dairy Specialist
Dairy Focus Communication
North Dakota State University Extension Service
